Tu Megajolt Users

[trogboy 17]

Right - I have been thinking about sorting out my ignition system as my dizzy seems to be dying slowly as the vacuum advance gives up the ghost which in my opinion is a good excuse for a mini project. I am really tempted to start running a megajolt mapable ignition system especially as I have been offered a ready built ECU to try out.

 

What I want to know is the practicalities of fitting this system to the TU engine.

 

MartinM and Brennan are already using this though I don't know if Brens is up an running yet. Plus has anyone managed to keep their tacho working?

 

For info I have a hybrid TU3/TU24 engine running twin Weber DCOMs on a TU24 head and manifold and the standard TU24 ignition system. The car was originally a standard UK spec rallye so it has always has never had distributorless ignition.

 

Any thoughts much appreciated.

 

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[bren_1.3 1]

which E.C.U type have you been offered? the M.A.P sensor or the TPS sensor type?

 

it will require a whole new loom to be made, but it will be self contained so easy to work with (check your emails. i sent you the wiring diagrams again)

[trogboy 17]

I'm not sure which type as I havn't looked in to it too much yet. Which is better?

 

What I am more interested in at the moment though is the mechanics of fitting all of the required parts to the engine/engine bay. I take it you have mounted the trigger wheel onto the crank at the timing belt end in some way. How did you manage this and go about mounting the sensor?

 

Tell me everything... (with pics )

 

I need your knowledge!

[bren_1.3 1]

ok Adam brace yourself. (and anyone else who might be interested.)

 

As you know the megajolt system runs the following components.

 

Ignition module (and leads)

EDIS module

Crank wheel

Crank sensor

TPS sensor / MAP sensor.

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Ignition amp and leads.

 

ingition module

 

the first link shows where i have mounted the ignition module. it is possible to fit the module anywhere, (that tyhe leads will allow, but ill come onto that) but ive mounted it here where the ignition amp used to be mounted for the following reason.

 

the ignition leads!

 

the ignition leads themselves are from a late TU 1.1 with single point injection.

the ignition amps themselves between the ford and peugeot items are very similair in design to each other, and the leads give a resounding click when pressed on.

 

see here as to where the peugeot ignition amp is located on the TU.

 

other people use the ford leads but i think the peugeot items are probably the best fit, and look O.E. dont worry about getting the leads mixed up either as the ignition module labels its leads.

------------------------------------------------------------------

EDIS module

 

the EDIS module itself can be located anywhere but you must remember than some of the wires that have to be joined are shielded, so its probably best to locate it as close to the megajolt E.C.U as possible, wherever that may be.

 

i located my megajolt E.C.U where the GTI E.C.U would sit under the dash. so ill probably mount the EDIS module down the drivers side of the engine bay somewhere probably where the scissor jack sits

 

picture on an EDIS module

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TPS sensor or MAP sensor.

 

AFAIK the map sensor takes a vacuum feed from the inlet manifold, the only problem being theres more than one runner so you'd have to take readings off all 4 cylinders or just two cylinders on a different cycle. so not 1&4 or 2&3. i think MAP sensors are more ideally suited to the GTI's plenum chamber than the multiple barrels of a carburettor setup.

 

the TPS sensor requires a couple of brackets knocked up, and is probably best suited for the weber setup. you can buy kits from people (i dont know who) that mount a TPS onto the side of the webers. but no doubt theyre expensive.

 

like so

 

i havent got all that far with it myself, suffice to say the weber TPS i bought does fit to the two holes in the above photo, but will require spacing out away from the spindle. i will also have to knock up a lever to operate the TPS. again i havent looked into it properly.

------------------------------------------------------------------------

 

crank wheel

 

quite easy to knock up. i bought a 36-1 wheel, although i cant remember its size. but if you look at the picture you'll see its the size of the alternator pulley so measure that to get a rough idea .

 

crank wheel.

 

To mount the crank wheel away from the alternator pulley bolts i had Martin M knock up a spacer for me.

i had to use the MEGA washer thats found on the crank pulley bolt in conjunction with the new washer to clear the alternator pulley bolts. (see photo)

 

i did have the idea of cutting down the bolt heads to gain a bit more thread back on the crank pulley bolt. but that would be a bit silly if they failed. You could use allen key button head bolts but your not going to gain much more clearance and in all honesty it isnt worth the hassle.

 

crank photo 2 (clearance issues)

 

that leaves the VR sensor or the crank sensor to you and me.

 

i havent knocked this up yet as it will require drilling intohere in order to mount it. instructions say it DOESNT have to be mounted right over the top of the sensor wheel but can be anywhere up to 90 degrees to the side of the wheel. it does however have to be about 1mm away from the wheel so this bracket can be tricky to make up, and will have to go over the top of the alternator pulley so alternator belt changes could become tricky and you'd almost certainly lose the plastic guards that surround the bottom of the engine.

 

HTH.

Edited May 4, 2007 by brens_1.9_wide_arch

[205Rallee 59]

I'm not sure which type as I havn't looked in to it too much yet. Which is better?

 

What I am more interested in at the moment though is the mechanics of fitting all of the required parts to the engine/engine bay. I take it you have mounted the trigger wheel onto the crank at the timing belt end in some way. How did you manage this and go about mounting the sensor?

 

Tell me everything... (with pics )

 

I need your knowledge!

 

I've got a virtually brand new Bosch Dizzy for the TU24 sitting in my garage.... Having gone down the non DIY route for 3D ignition on my TU24, it runs quite well, but cost quite a lot!

[trogboy 17]

...cutting down the bolt heads to gain a bit more thread back on the crank pulley bolt.

 

You are still using the standard crank pulley bolt then?

 

Did the pulley wheel come from Martin?

 

I appreciate the reply by the way, it must have taken a serious amount of time to prepare.

[bren_1.3 1]

You are still using the standard crank pulley bolt then?

 

yeh i still have a slight concern about it. but i wouldnt know where to get a longer one from!

 

Did the pulley wheel come from Martin?

 

no it didnt but he can supply them i think. are you in discussions with him?

 

I appreciate the reply by the way, it must have taken a serious amount of time to prepare.

 

no worries! still have to get those pistons sorted out for you aswell!

[christopher 5 1 Cars]

Bren,

 

This really sounds very interesting. But what about time and effort for the install & price.

 

I mean QEP offers the ignition only module for about 200 odd. What are the advantages of this setup over that?

[trogboy 17]

Hi Chris,

 

It is an interesting question!

 

From what I have read the KMS system sold by QEP is compatible with Bosch ignition systems and can use the 60-2 timing wheels so on the face of it may be tidier and possibly easier to slot into a carbed TU engine as you can probably make use of the coil, leads, timing wheel and crank sensor from the injection TUs. This should then be easy to find parts whilst keeping it as PSA as possible.

 

On the other hand the set up costs potentially 2-3 times the cost of a megajolt and you may not get as much of a 'I did that' feeling at the end of it.

 

The KMS system should be quicker to fit and of course you don't have to build your own ECU!

 

What about support? Do many people run the KMS system and know the potential pitfalls and problems. I happen to work with a guy that is helping to develop the next megajolt/megasquirt packages, so for me technical help is literally a few seconds away.

 

I have to say though I'd rather keep it PSA if I could. Perhaps if a foray into megajolt proves successful I would look at changing in the long run once I have a better idea of what I am doing, what I am capable of and what I want for the car.

 

At the moment I would feel a bit apprehensive about spending a couple of hundred pounds on something which may end up being a shiny paperweight.

 

How's your engine build in the basement coming along?

[bren_1.3 1]

This really sounds very interesting. But what about time and effort for the install & price.

 

there has been no sustained effort from me in sorting the whole thing out. i havent come across any major headaches, more like i havent been arsed to do much with it. i know where all the components will go and the wiring is pretty simple. its probably a weeks work in the workshop though knocking up a few brackets.

 

if QEP sells KMS at £200 squid for EVERYTHING then thats fine, i havent looked into the KMS setup, and as im halfway through this install i see no real reason to abandon what ive already got in favour of whatever KMS has. id hedge my bets by saying that the KMS all told would probably be over the 200 pound mark as adam suggests though.

 

my costs so far have been:

 

£40 - trigger wheel

£40 - VR sensor / EDIS module / Ignition module

£87 - E.C.U and shift lights

£25 - TPS sensor (overpriced and i needed one)

FOC - ignition leads.

 

so im roughly at £200 pounds as is. you could go and find most of the components down the scrappie for next to nothing if you had the time. the only thing you absolutely have to fork out for is the E.C.U and the trigger wheel.

 

i think its all about budget really. megajolt/squirt is always going to have that DIY feel about it. where as the KMS jobbie would probably be a bit more factory.

 

you can use the software supplied and simply hook the E.C.U up to a mates laptop and get cracking. martinM supplied me with a map for a vauxhall redtop and a 1600 gti. you could im sure get an ignition map from somwhere for a boggo TU so you wouldnt be far off the pace to begin with. again as adam suggests setup costs from a KMS "dealership" are going to add to the price again.

 

so id conclude its really about budget and mechanical know-how. do you have the time and ability to put together something that may look daunting but is actually rather simple.

 

EDIT: i got my E.C.U ready built, another big plus.

Edited May 5, 2007 by brens_1.9_wide_arch

[christopher 5 1 Cars]

This should then be easy to find parts whilst keeping it as PSA as possible.

 

Hi Bren,

 

I have been considering moving to a mappable ignition but since this is technically not really allowed then I want to look as stock as possible. Removing the dizzy also frees up a little space in the area where I can place some decent cold air ducting to the carbs. I want a system that I can easily adjust based on my engine setup. Since fuel is not involved I'm hoping that a DIY setup might not be that involved but I may be wrong here.

 

How's your engine build in the basement coming along?

 

I'm afraid it has been rarther delayed due to me renovating a house:-( I have sourced many parts but have not got started in the bottom end rebuild. The head however is finished. I'm up a considerable 15% odd on stock flow. In the mean time she is feeling a little sorry for herself. squeak..rattle..

Edited May 7, 2007 by christopher

[TKH 0]

Whatever system you go for I would highly recommend only going for a system with a 3D mappable ignition map.